Carya kweichowensis Seeds | Guizhou Hickory
LATIN NAME: Carya kweichowensis
COMMON NAME: Guizhou Hickory
Plant Profile
Guizhou hickory is a tree that barely exists in horticulture, and what is known about it comes mostly from the type material and a handful of forest surveys. It was described in 1979 from the mountains of Guizhou, and it is a medium to large deciduous tree with pinnate leaves of five to seven leaflets, a straight trunk and a broad crown, growing in mixed broadleaf forest on limestone and acid soils. The nuts are small, thick-shelled and borne in thick husks, and they are edible but difficult. It is one of a group of Chinese hickories that are still being sorted out taxonomically, and its relationship to the more widespread Chinese hickory, Carya cathayensis, is not settled. It is of interest to collectors, to breeders looking for hardiness, and to anyone documenting the tree flora of southwestern China.
Science & Biotechnology
Carya kweichowensis belongs in section Sinocarya, the Asian hickories, and it is one of the species whose limits are still argued. The genus has 2n = 32, and the Asian species are distinguished from the American ones by having fewer leaflets and, generally, thicker nut shells. The species is heterodichogamous, with male and female flowers maturing at different times, and it is wind-pollinated, which is why hickories in cultivation need to be planted in groups to set good crops. Its restricted distribution in the mountains of Guizhou, in a region of high endemism and rapid habitat change, makes it a species of conservation interest, though it has not been formally assessed. The wood is hard, shock-resistant and valuable locally, and the nut oil is similar in composition to that of other hickories.
Uses & Benefits
The nuts are gathered locally and eaten roasted or pressed for oil, as with the other Chinese hickories, and the oil is used for cooking. The timber is hard and takes shock well and goes into tool handles and furniture, though the tree is too rare to be a timber species of any consequence. Its main value is as a genetic resource: it is a close relative of the commercial Chinese hickory, and it may carry genes for hardiness, disease resistance or nut quality that breeding programmes could use. In gardens it is a collector’s tree, grown for the handsome foliage, the yellow autumn colour and the novelty of the nuts, and it is rarely offered. It is slow to establish and slow to bear, and it needs a deep soil and a long growing season to ripen its wood.
Growing from Seed
Treat it like the other hickories: sow fresh nuts in autumn, two to three centimetres deep in a deep pot, and leave them outdoors for winter, since they need cold, moist stratification and must not dry out. Protect them from rodents. Germination is in spring, and the seedling makes a long taproot in the first season, so use a deep container and do not trim the root. Grow it in full sun in deep, well-drained, slightly acid soil, and keep it free of competition. Plant out at forty to sixty centimetres in a site with room for a large crown, and water through the first two summers. Expect slow growth, ten years or more to the first nuts, and a tree that rewards patience rather than speed.
Our Take
A rare Chinese hickory for collectors and breeders, with hard-shelled nuts and handsome foliage. Plant it in deep soil and expect to wait a decade.
Related Reading
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